Let's get this math done. We have 717 and we're going to multiply it by 20. This is the same as taking 717 and adding it to itself 20 times.
Step 1: 0 + 717 = 717
Step 2: 717 + 717 = 1434
Step 3: 1434 + 717 = 2151
Step 4: 2151 + 717 = 2868
Step 5: 2868 + 717 = 3585
Step 6: 3585 + 717 = 4302
Step 7: 4302 + 717 = 5019
Step 8: 5019 + 717 = 5736
Step 9: 5736 + 717 = 6453
Step 10: 6453 + 717 = 7170
Step 11: 7170 + 717 = 7887
Step 12: 7887 + 717 = 8604
Step 13: 8604 + 717 = 9321
Step 14: 9321 + 717 = 10038
Step 15: 10038 + 717 = 10755
Step 16: 10755 + 717 = 11472
Step 17: 11472 + 717 = 12189
Step 18: 12189 + 717 = 12906
Step 19: 12906 + 717 = 13623
Step 20: 13623 + 717 = 14340

So, 717*20 = 14340